In large saucepan melt butter over medium high, reduce heat medium. Add Strained tomatoes (there will be some liquid left in tomato and that is good). Cook for about 1 minute. Add garlic and continue cooking for 3 minutes.
Sprinkle with about half of the flour and mix well.
Add chicken broth and cook until bubbles form but not bubbling. Add half and half and stir well. Add thyme, cumin, salt and pepper.
This part is tricky and hopefully not too confusing...Using a slotted spoon scoop out the tomatoes and transfer to a food processor (smallest one you have, I use a 2 cup one). Sprinkle with remaining flour and blend until smooth. Return to saucepan and mix well.
Continue stirring until bubbling and mixture thickens.